ACS Omega
·
2017
·
IF 0
Hailong Fan,Jiahui Wang,Qiuya Zhang,Zhaoxia Jin
Adhesiveness of hydrogels depends on the balance and synergy of their cohesion and adhesion. However, it is a challenge to fabricate catechol-based hydrogels with high adhesiveness because the required condition for cohesion and adhesion of these hydrogels is in conflict with each other: strong cohesion (gelation) requires a weak basic condition, whereas strong adhesion requires an acidic condition. Here, we demonstrated that by utilizing polyphenol supramolecular chemistry, the coexistence of strong cohesion and adhesion can be achieved in a hydrogel via the one-pot method. Poly(dimethyl diallyl ammonium chloride)/tannic acid (PDDA/TA) hydrogel has been studied as a proof of concept. Compared with catechol moieties that covalently grafted on polymer chains, TA can bring high density of pyrogallol/catechol functional groups for polymers via a noncovalent pathway, as well as high acidity in the system. As a result, the cohesion of the hydrogel is enhanced significantly, the highest storage moduli can reach up to ca. 0.15 MPa; besides, the high acidity of the hydrogel prevents pyrogallol/catechol groups from oxidation and guarantees strong adhesion; thus, the hydrogel can adhere to diverse substrates steadily, including tissues, glass, metals, and plastic. Moreover, because of the adjustable adhesiveness via changing the pH, the PDDA/TA hydrogel becomes a unique system with patternable adhesiveness. In addition, the hydrogel has rapid self-healing and high ionic conductivity (∼4.3 S m–1). This study demonstrates that utilizing polyphenol chemistry in the construction of hydrogels opens a new path toward multifunctional hydrogels with improved properties.
研究领域:
材料科学
·
生物医学工程
✓ 已验证
DOI
CARBOHYDRATE POLYMERS
·
2021
·
IF 9.381
Xue-dong Wang,Ya Li,Tao-tao Dai,Xue-mei He,Ming-shun Chen,Cheng-mei Liu,Rui-hong Liang,Jun Chen
Novel pectin/poly(m-phenylenediamine) (P/PmPDA) microspheres with different content of PmPDA were prepared by assembling PmPDA on the surface of pectin microsphere. The successful preparation was confirmed by the results of Fourier Transform Infrared spectra (FTIR), scanning electron microscopy (SEM) and elemental analysis. Compared with pectin microsphere, the Pb 2+ adsorption performance of P/PmPDA microspheres was significantly improved. The results of batch adsorption experiments were in good agreement with the Langmuir isotherm model for Pb 2+ adsorption, indicating the adsorption was monolayer. The maximum adsorption capacity of Pb 2+ was found to be 390.9 mg/g. The kinetic adsorption process was well described by the pseudo-second-order model and chemical adsorption dominated the adsorption process. The potential mechanisms of Pb 2+ adsorption were speculated as ion exchange and chelation, which were supported by X-ray photoelectron spectroscopy (XPS). The P/PmPDA microspheres showed good recyclability after five adsorption/desorption cycles. All these results indicated the potential of P/PmPDA microspheres for removing Pb 2+ .
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
PubMed
高影响因子
Journal of Environmental Chemical Engineering
·
2021
·
IF 5.909
Liying Jiang,Zhiwei Yao,Pengju Wang,Jianmeng Chen,Yufen Zhang,Wu Huang,Xiang Cao,Yufeng Xu
Plasma-catalytic removal of chlorobenzene (CB) was conducted in a dielectric barrier discharge (DBD) reactor over two manganese-based catalysts, LaMnO 3 and cryptomelane-type octahedral molecular sieve (OMS-2). The physicochemical properties of two catalysts were characterized by XRD , SEM, TEM , BET, XPS and H 2 -TPR. It was shown that OMS-2 catalyst had larger surface area, smaller particle size, better redox properties, higher ratio of Mn 4+ /Mn 3+ and higher content of surface-adsorbed oxygen (O ads ). The introduction of manganese-based catalysts enhanced CB removal, increased the CO 2 selectivity , and inhibited ozone (O 3 ) and NO x formation. OMS-2 exhibited a better degradation, mineralization and energy yield, with 89.5% of CB degradation, 57.6% of CO 2 selectivity and 0.54 g kWh −1 at discharge voltage of 6 kV, than LaMnO 3 in the NTP-catalytic reactor and this was ascribed to more active sites, more O ads , higher redox property and better O 3 decomposition ability on OMS catalyst surface. The two manganese-based catalysts were stable in the NTP-catalysis system although some intermediate byproducts were deposited on the catalyst surface during the 24-h activity cycling tests. Moreover, the intermediate byproducts were analyzed by GC/MS, and then the possible degradation pathways of CB decomposition in the plasma-catalysis system were suggested.
研究领域:
环境科学
·
催化化学
✓ 已验证
DOI
高影响因子
MACROMOLECULAR CHEMISTRY AND PHYSICS
·
2019
·Vol. 220
·期 12
·1900061
·
IF 2.622
Liang Zhao,Lin Zhang,Zelai Zheng,Ying Ling,Haoyu Tang
Homopolypeptide bearing azobenzene and triethylene glycol spacers, and 1-butylimidazolium pendants, namely P(Azo-OEG 3 -ImX) (X = Cl, I, BF 4 ) are prepared by 1,3-dipolar cycloaddition and subsequent ion-exchange reaction. Both 1 H NMR and FTIR confirm the polymer structures and reveal a high grafting efficiency (97%). P(Azo-OEG 3 -ImI) shows reversible upper critical solution temperature (UCST)-type thermoresponsive property in ethanol while P(Azo-OEG 3 -ImI/BF 4 ) shows a UCST in ethanol/water solvent mixtures. P(Azo-OEG 3 -ImI) shows UCST-type phase transitions in ethanol or ethanol/water solvent mixtures. After UV irradiation, the UCST-type cloud point temperature ( T cp ) remains constant in ethanol. However, it decreases after UV irradiation and increases after visible light irradiation in ethanol/water solvent mixtures due to the trans – cis isomerization of azobenzene moieties. P(Azo-OEG 3 -ImCl/I) shows NaI-induced UCST in water. The T cp of the P(Azo-OEG 3 -ImCl/I) aqueous solution is highly related to the polymer/salt concentration and nature of counteranions. P(Azo-OEG 3 -ImCl) also shows reversible light-responsive properties in NaI aqueous solutions. Higher NaI concentration is needed to induce a UCST for P(Azo-OEG 3 -ImCl) after UV irradiation. Moreover, ciprofloxacin-loaded hydrogel containing P(Azo-OEG 3 -ImCl) shows more efficient drug release while the UV irradiation leads to slightly low drug release.
研究领域:
高分子化学
·
材料科学
✓ 已验证
DOI
高影响因子
JOURNAL OF MOLECULAR STRUCTURE
·
2024
·
IF 4
Yue Zhao,Mingya Wang,Junli Shi,Mingfeng Han,Yuqi Wu,Shengling Li,Linxiu Zhao,Duanlin Cao
In this paper, a fluorescent probe methyl( E )-2-(3-(benzo[ d ]thiazol-2-yl)-2‑hydroxy -5-methylbenzylidene) hydrazine-1-carboxylate ( DYH ) based on benzothiazole was designed and synthesized. The characterization involved NMR, HRMS, and crystal structure analysis. In case of the existence of other competing cations, the probe DYH showed high-affinity for Cu 2+ , and the resultant DYH Cu 2+ showed exceptional capacity to recognize S 2− in CH 3 CN/HEPES (7/3, v/v, HEPES 0.1 M, pH = 7.3). The detection limits of DYH for Cu 2+ and DYH Cu 2+ for S 2− were 0.56 μM and 0.67 μM, respectively. It was determined that the binding stoichiometry between the DYH and Cu 2+ , as well as DYH Cu 2+ and S 2− , was 1:1 according to the job's curve. The pH of the probe and complex was stable between 4 and 10. Colorimetric experiments of the probe DYH were conducted using test paper as a carrier. Additionally, DYH was used for fluorescence imaging of Cu 2+ and S 2− in Hela cells with poor cellular toxicity and good cell permeability.
研究领域:
分析化学
·
生物医学
✓ 已验证
DOI
高影响因子
BIORESOURCE TECHNOLOGY
·
2015
·
IF 4.494
Shengnan Shi,Yuanyuan Qu,Hao Zhou,Qiao Ma,Fang Ma
Arthrobacter sp. W1 was used to characterize the pathways involved in cometabolic degradation of carbazole (CA) with phenol as the primary substrate. To clarify the upper pathway of cometabolic degradation CA, Escherichia coli strain BL21 expressing phenol hydroxylase from strain W1 (PH IND ) was investigated to degrade CA. Firstly, CA was initially monohydroxylated at C-2 and C-4 positions to produce 2- and 4-hydroxycarbazole, followed by successively hydroxylated to the corresponding 1,2- and 3,4-dihydroxycarbazole, of which 3,4-dihydroxycarbazole was unequivocally identified for the first time. To characterize the downstream cometabolic degradation CA pathway, purified 3,4-dihydroxycarbazole was used as the substrate for phenol-grown W1, and a series of novel indole derivatives were identified. These results suggested that a novel pathway of CA catabolism was employed by strain W1 via a successive hydroxylation and meta -cleavage pathway. These findings provide new insights into the cometabolic degradation CA process and have potential applications in biotechnology and bioremediation.
研究领域:
微生物学
·
环境科学
·
生物技术
✓ 已验证
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2013
·Vol. 131
·期 4
·
IF 1.395
Ruihua Huang,Bingchao Yang,Qian Liu,Yanping Liu
Activated carbon/chitosan composite has been used as an adsorbent to remove aniline and Cr(VI) ions from aqueous solutions simultaneously. The effects of preparation conditions such as the ratio of activated carbon to chitosan, crosslinking reagents, crosslinking time, and adsorption conditions including adsorbent dosage, pH value of solution, and contact time on simultaneous adsorption of aniline and Cr(VI) ion were investigated. Experimental results showed that epichlorohydrin was the proper crosslinking reagent, and the ratio of activated carbon to chitosan was kept at 1. When the adsorbent dosage was 4.0 g/L, and the concentrations of aniline and Cr(VI) were lower than 50 and 100 mg/L, respectively, both aniline and Cr(VI) were simultaneously removed at natural pH with high removals (>95%). The presence of Cr(VI) enhanced the adsorption of aniline, while the presence of aniline almost had no influence on the adsorption of Cr(VI). The adsorption processes of both aniline and Cr(VI) followed the pseudo-second-order kinetics model, but the sorption of Cr(VI) was preferential to that of aniline by this composite. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131 , 39903.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
APPLIED CATALYSIS A-GENERAL
·
2020
·
IF 5.006
Renjie Deng,Kuiyi You,Wenjin Ni,Fangfang Zhao,Pingle Liu,He’an Luo
In this work, we developed a low-temperature and efficient approach for the highly selective preparation of valuable p -nitrochlorobenzene from the liquid-phase catalytic nitration of chlorobenzene with NO 2 in O 2 -Ac 2 O-Hβ composite system. The results demonstrated that the introduction of molecular oxygen remarkably enhanced the chlorobenzene conversion and the cooperation catalysis of Hβ zeolite and Ac 2 O envidently improved the selectivity to para -nitro product. Under the optimized reaction conditions, 93.6 % of the selectivity to p -nitrochlorobenzene with 84.0 % of chlorobenzene conversion was obtained, and the ratio of p -nitrochlorobenzene to o -nitrochlorobenzene could reach up to 20.3. Furthermore, the selectivity distribution of nitration products was reasonably explained by the density functional theory (DFT) calculation. Finally, the possible nitration reaction pathway of chlorobenzene with NO 2 was suggested in O 2 -Ac 2 O-Hβ composite catalytic system. The present work affords a new and mild nitration approach for highly selective preparation of valuable para -nitro products, and has potential industrial application prospects.
研究领域:
化学工程
·
催化
·
有机化学
✓ 已验证
DOI
高影响因子
iScience
·
2021
·
IF 5.458
Qing-Nan Wang,Xianghui Liu,Kai Wang,Yan Liu,Sheng-Mei Lu,Can Li
Summary p -Methyl benzaldehyde ( p -MBA) is a class of key chemical intermediates of pharmaceuticals. Conventional industrial processes for p -MBA production involve the consecutive photochlorination, amination, and acid hydrolysis of petroleum-derived p -xylene, while producing vast pollutants and waste water. Herein, we report a direct, green route for selective synthesis of p -MBA from acetaldehyde using a diphenyl prolinol trimethylsilyl ether catalyst. The optimized p -MBA selectivity is up to 90% at an acetaldehyde conversion as high as 99.8%. Intermediate structure and 18 O-isotope data revealed that the conversion of acetaldehyde to p -methylcyclohexadienal intermediates proceeds in an enamine-iminium intermediate mechanism. Then, controlled experiments and D-isotope results indicated that the dehydrogenation of p -methylcyclohexadienal to p -MBA and H 2 is catalyzed by the same amines through an iminium intermediate. This is an example that metal-free amines catalyze the dehydrogenation (releasing H 2 ), rather than using metals or stoichiometric oxidants.
研究领域:
有机化学
·
催化
·
绿色化学
✓ 已验证
DOI
高影响因子
RESEARCH ON CHEMICAL INTERMEDIATES
·
2023
·Vol. 49
·期 7
·3029-3044
·
IF 3.3
Deng Renjie,Cui Haishuai,Liu Meilin,Ni Wenjin,Tian Yao,Liu Huajie
Different solid superacid sulfated zirconium dioxide (SO 4 2− /ZrO 2 ) samples were successfully prepared by conventional and ultrasonic-assisted chemical precipitation process, and then, they were characterized by X-ray diffraction, Fourier transform infrared, thermal gravimetric analyzer (TGA), nitrogen adsorption–desorption, ammonia temperature programmed desorption (NH 3 -TPD) and pyridine adsorbs Fourier transform infrared. The results of characterizations indicate that the sulfonic acid group is successfully introduced, and the acidity and surface area of sulfated sample can be increased by using ultrasonic method. Furthermore, this ultrasonic-assisted catalyst was used for the chlorobenzene nitration using nitrogen dioxide (NO 2 ) as nitrating agent. The catalyst shows excellent catalytic activity and reusability for the nitration of chlorobenzene giving high para -selectivity. In the optimal reaction conditions, the conversion of chlorobenzene can reach 85.2% with 88.5% selectivity to para- nitrochlorobenzene ( p -NCB). Furthermore, the reaction mechanism was proposed by combination of experimental results and theoretical calculations. The present work provides an easy-to-implement, mild and environmentally friendly approach for the efficient preparation of valuable p -NCB, which has extensive industrial application prospects. Graphical abstract
研究领域:
催化
·
有机化学
·
材料科学
·
化学合成
·
环境化学
✓ 已验证
DOI
高影响因子
Journal of CO2 Utilization
·
2017
·
IF 4.292
Lijun Zhao,Haiyang Cheng,Tong Liu,Yan Li,Zhong Ying,Wenjing Yang,Weiwei Lin,Xiangchun Meng,Chengxue Wang,Fengyu Zhao
An efficient green process was developed for production of p -aminophenol (PAP) from hydrogenation of nitrobenzene (NB) over a traditional Pt/Al 2 O 3 catalyst in a reaction medium of supercritical CO 2 (scCO 2 ) and H 2 O without any additional acid catalyst involved. The combination of scCO 2 and H 2 O was confirmed to be effective for the production of PAP. The acidity, aroused by the in situ formed carbonic acid, increased with CO 2 pressure, which acted as acid catalysis during the reaction, and it can easily self-neutralize by depressurization of CO 2 , resulting in a green and a intensive process for it removed the final neutralization and salts disposal of the traditional liquid acids. Under the optimal reaction conditions, a high yield to PAP (68.9%) was achieved at the high conversion of NB (98.5%). Moreover, the results of in situ diffuse reflectance FTIR spectra revealed that CO was generated by the reverse water-gas shift reaction (CO 2 + H 2 → CO + H 2 O), it can adsorbed on the surface of Pt/Al 2 O 3 to suppress the undesired deep hydrogenation of N -phenylhydroxylamine (PHA) to aniline (AN), which also contributed to the obtained high selectivity of PAP. Therefore, the present green and efficient catalysis process will arouse the interest of researchers in the fields of the green and sustainable organic synthesis.
研究领域:
绿色化学
·
有机合成
·
催化化学
·
环境友好工艺
·
工业化学
✓ 已验证
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2015
·
IF 5.056
Ling Ling Xia,Cai Lian Li,Yan Wang
In this work, two novel poly(vinyl alcohol) (PVA)/organosilica hybrid membranes are developed via the sol–gel process, with phenyltriethoxysilane (PTES) and diethoxydiphenylsilane (DEDPS) as crosslinkers and organosilica precursors, and employed for ethanol dehydration via pervaporation . Effects of organosilane type on the membrane morphology, physicochemical properties and pervaporation performance of the as-fabricated membranes are studied. In addition, the effects of the organosilane loading and the thermal treatment temperature on the physicochemical properties and pervaporation performance of the membrane are explored systematically. Various characterization techniques (FT-IR, TGA, SEM , etc) are employed to illuminate physicochemical changes of membranes. The optimal pervaporation performance of PVA–PTES hybrid membrane with 0.4 mmol/g PTES loading and thermally treated at 80 °C has a flux of 145 g/m 2 h and a separation factor of 1026 for the pervaporation dehydration of 85% ethanol aqueous solution at 40 °C.
研究领域:
化学工程
·
膜科学
·
材料科学
·
分离技术
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）